Electric switch



1,638,658 Aug- 9 1927- y H. o. ENGsTRoM ELECTRIC SWITCH Filed June ll,1924 INVENTOR. HE/vm/ 0. E/vGsT/'om J Q fre iwf' ,that

una o. nnesfraom, or Bnrnenron'r, connnc'r'rcu'r, assrenoa 'ro man naw nsanrcoonrnm, or ngarncnron'r, connncrrou'r, A

enamore er cora- Application led J'une 11, 1924, Serial No. H9393.

My invention relates to electric switches, and particularly to switches.of the pushthrough type. e object of Imy invention is to provide asimple and inexpensive switch mechanism which :may be readilymanufactured and assembled, and is edicient in service.

In the accompanying drawings- Fig. 1 is a vertical section through anelecw tric fitting in which a switch embodying my invention in one formis shown;

Fig. 2 is a .section on the line 2-2, Fig.. 1;

ldig. 3 is a section on the line 3-3, Fig. 1; an ,15 Fig. 4 is an endview of a lamp socket in which the vswitch is here shown installed.

While have shown my invention embodied in aflamp socket, it will beunderstood that .thefswitch mechanism, to which w myinvention-particularly relates, may be used in any appropriate type offitting, and -its utility is not confined to lampv sockets. The lampsocket installation illustrates merely an appropriate use of the switch.

The socket shown commises :a usual metallic casing shell 15, withseparable cap 16, both lined with insulation 17 and constituting ahousingxfor the socket body and its associated parts. In its generalfeatures the socket body resembles that illustrated in the copending.application of Carl Eric Anderson, Ser. No. 713,277, filed May 14,1924, and comprises aporcelain button 18 and an associated washer 19arranged at one end of the button, the latter supporting the screw shelllamp terminal 20 and center con tact 21, and both of the wireterrninals22 and23. The? wire terminal 22 is directly connected to the screw shellterminal 20, while the wire terminal 23`is provided with an odset flange24 which projects into the switch chamber 25 and constitutes one of theswitch contacts.l 'The base Hange ofthe cooperatin switch contact 26 isengaged by the rivet 2g? which holds .the center contact 21 to theouter' face ofthe disc 19. The circuit is thus made and broken on thecenter.

contact of the socket.

The switch mechanism comprises a rectilinearly movable push plate 28having at its opposite ends push buttons 29 which project t roughsuitable ide openings 30 in the insulating linin and shell 15 of thecasing. The push p ate passes through the switch chamber 25 intermediatethe contacts 24 and 23 and is guided in slots 31 and 32 (Fig. 3) whichextend between the switch chamber .and the bays 33 and 34 whichaccommodate the inner ends of the push buttons 29. rlhe push plate isformed from sheet metal, and is provided intermediate its ends wlth apeaked cam 35, the inclines of which terminate in legs 36 and 37, theengagement of which in the guide, slots 31 and y 32 prevents lateralplay, while their length is I sufficient to prevent longitudinal tiltingo1 the plate b v reason of its engagement between the disc 19 and thebottoms of the guide slots 31 and 32 in the button 1 8.Y

Riding the cam 35 is the switch piece 38.

The latter is also `struck from sheet metal,v

and its head is of suiiicient transverse extent to bridge the contacts24 and 28, as shown4 in Figs. 2V and 3. The shank 39 projecting from thehead of the 4switch piece passes to the side of the push plate 28 andextends toward a well formed in the button y18` and opening to theswitch chamber 25. foot piece 41 is offset from the leg 39 across thepush plate 28 and is apertured to receive one end of a pull coil spring42. The opposite end of the latter engages a depressed broad web 43between the ends of a narrow bearing plate 44, which lines the bottomsof the slots 31 and 32, and against which the lower ends of the legs. 36and 37 ofthe push plate are held in bearing engagement by the spring 42.A notch in the lower marginl y of the head 38 of the 'switch piece,accommodates the peaked cam 35 of the push bar, and the engagement ofthe switch plate .therewith -is constantly maintained by' the stress ofthe pull spring 42. The push plate 28, bearing plate 44, switch piece 38andspring' 42 thus form an assembly unit, selfcontained andself-maintained by the stress 1 of thespring. A The operation of themechanism is readil understood. In Figs. 1, 2 and 3 the switc is shownin circuit-closing position, that is to say with the sw1tch piece 38bridging the contacts-'24 and 26. '1f the push plate be.

shifted to the left, the switch piece 38 (retained against movementtherewith by its engagement with the contacts 24 `and 26) is forced toride up the incline a of the cam 35, thus wiping the engaged surfaces ofthe contacts and further stressing the spring 42.

As the peak of the' cam 35 passes the switchy piece 38, the spring'42causes the latter to run down the opposite incline I) of the cam, andthus move rapidly across the switch chamber 25, against the oppositewall of which it is halted in open-circuit. position..

During the transverse shifting of the push plate, its legs ride I thebearinv plate 44, which is thus= held against dlsplacement under theincreased stress of the spring 42.

- Longitudinal displacement of the plate 44 is prevented by theengagement of its depressed web 43 in the well 40. It will thus beobserved that the bearingv plate which forms the element to which oneend of the spring is anchored, is held in position by thel push platewhich tensions the spring, while at the same time it affords a goodbearing surface for the ends of the webs 36 and 37, and obviates thenecessity for iinishing the surface ofthe porcelain at the bottoms ofthe slots 31 and 32 upon which the legs of the vpush plate wouldotherwise bear with considerable friction. A smooth operation .of

vthe push plate is'. provided and at the same time a simple and secureanchorage for the fixed end of the spring 42. t

To assemble the parts it 1s only necessary to pass the push bar assemblyunit into the switch chamber and guide slots'of the button 18 untiltheyl bottom therein. The disc.

19, with the conductors assembled thereon, may then be mounted at theend of the button and the parts secured together. by the two holdingbolts 461Which pass through the' button 18 and dis`c19 and engage,respectively, the nut 47 andthe tail 48 ofthe wire terminal 22, whichoverlies the base ange 49 of the 'screw shell contact 20. The assemblyoperation is thus exceedingly simple and expeditious, while themechanism is efficient and unlikely to become deranged.

actuator against the guideway lining. In testimony whereof I have signedmy.

Lesas Various modications in details of construction will readily occurto those skilled Ain the art which do not depart from what lI claim asmy invention.

2. Inl an electric switch, an assembly unitl comprising a rectilinearlymovable actuator' with peaked cam, a switch piece riding said cam,l abearing plate and a switch operating spring interposed between saidbearing plate and switch piece and serving to hold the parts inself-contained assembled relation. A

3. In an electric switch, an insulating body recessed to afford a switchchamber, a well and a guideway opening thereto, a rectilinearly movablepeaked cam actuator traversing the chamber and guideway, a switchpieceriding the actuator cam,-a combined spring anchor and guideway lining,having a portion offset into said well, and a spring engaging saidoti'set portion of thelining member and extending between the switchpiece and anchor and serving' to hold thc name to this specification.

HENRY o. ENGsTRoM.

